javascript - Angular if/else 开关

Question

我列出的文章有封面图片，但有些也有外部链接，例如 youtube。如果他们有外部链接，我应该显示 iframe，如果他们没有链接，我应该显示封面图像。我不知道该怎么做，我对 Angular 还很陌生。我可以在 Controller 中以某种方式设置它还是应该在 View 中执行一些 ng-switch 语句？ 这是我试图实现的代码的一部分:

<!--  what I need is something like if external_media.length != 0 -->
<iframe src="{{ article.external_media.original_url}}"></iframe>
<!-- else -->
<img src="http://coop.app/imagecache/cover/{{article.cover_image}}">

这就是我从文章中获取的数据的样子。

117:Object
  category_id:1
  challenge_id:1
  comments:Array[3]
  cover_image:"1465913551.5549-photo-1460378150801-e2c95cb65a50.jpeg"
  created_at:"2016-06-14 14:14:12"
  external_media:Array[1]
    0:Object
    article_id:117
    created_at:"2016-06-14 14:14:13"
    id:1
    original_url:"https://www.youtube.com/watch?v=p9ELYMhJZlI"
    updated_at:"2016-06-14 14:14:13"
    url:"https://www.youtube.com/embed/p9ELYMhJZlI?feature=oembed"

这是我的观点:

<ion-item ng-repeat="article in articles" href="#/main/article/{{article.id}}" class="item-light">
  <div class="article">
  <!--  what I need is something like if external_media.length != 0 -->
  <iframe src="{{ article.external_media.original_url}}"></iframe>
    <!-- else -->
    <img src="http://coop.app/imagecache/cover/{{article.cover_image}}">
    <h1>{{ article.title.split(' ', 7).join(' ') }}</h1>
  </div>

  <div class="row">
    <div class="col col-20">
      <a href="#" class="subdued">
        <i ng-click="like(article)" ng-class="{ 'ion-ios-heart' : article.like == 1, 'ion-ios-heart-outline' : article.like == 0}"></i> Lik
      </a>
    </div>
    <div class="col col-70">
      <a href="#" class="subdued">
        <i class="icon ion-ios-chatbubble"></i> {{ article.comments.length }} Kommentarer
      </a>
    </div>
    <div class="col col-10 right">
      <a href="#/main/article/{{article.id}}" class="subdued">
        <i class="icon ion-chevron-right"></i>
      </a>
    </div>
  </div>
</ion-item>

更新的代码:

我已尝试了答案中的建议，但我可以在 iframe 中获取视频。我得到了视频的链接，但 iframe 中没有显示任何内容。这是代码:

<img ng-show="article.external_media.length == 0 || article.external_media.url == ''"  src="http://coop.app/imagecache/cover/{{article.cover_image}}">
        <iframe ng-show="article.external_media.length > 0 && article.external_media.url != ''" src="{{ article.external_media[0].url}}"></iframe>
        {{ article.external_media[0].url}}
          <h1>{{ article.title.split(' ', 7).join(' ') }}</h1>
        </div>

Answer 1

这是使用 ng-show (doc) 的可能性

我添加了什么？

<img ng-show="article.external_media.length == 0 || article.external_media.url == ''"  src="http://coop.app/imagecache/cover/{{article.cover_image}}">
<iframe ng-show="article.external_media.length > 0 && article.external_media.url != ''" src="{{ article.external_media.original_url}}"></iframe>

对于图像:它将检查是否没有 external_media 或 url 为空

对于 IFrame :它将检查是否存在 external_media 以及是否存在 url

大家一起

<ion-item ng-repeat="article in articles" href="#/main/article/{{article.id}}" class="item-light">
  <div class="article">
  <!--  <img src="{{ fileServer }}/imagecache/cover/{{article.cover_image}}"> -->
    <img ng-show="article.external_media.length == 0 || article.external_media.url == ''"  src="http://coop.app/imagecache/cover/{{article.cover_image}}">
    <iframe ng-show="article.external_media.length > 0 && article.external_media.url != ''" src="{{ article.external_media.original_url}}"></iframe>
    <h1>{{ article.title.split(' ', 7).join(' ') }}</h1>
  </div>

  <div class="row">
    <div class="col col-20">
      <a href="#" class="subdued">
        <i ng-click="like(article)" ng-class="{ 'ion-ios-heart' : article.like == 1, 'ion-ios-heart-outline' : article.like == 0}"></i> Lik
      </a>
    </div>
    <div class="col col-70">
      <a href="#" class="subdued">
        <i class="icon ion-ios-chatbubble"></i> {{ article.comments.length }} Kommentarer
      </a>
    </div>
    <div class="col col-10 right">
      <a href="#/main/article/{{article.id}}" class="subdued">
        <i class="icon ion-chevron-right"></i>
      </a>
    </div>
  </div>
</ion-item>